Clinical evidence suggests that steroids are not the only factors involved in the development of benign prostatic hyperplasia (BPH). We have found high molecular weight mitogenic factors present inhuman prostatic homogenates and expressed prostatic secretions. We are therefore going to purify these non-steroidal prostate mitogenic factors (PrGF) and compare them to other known mitogens. We propose to make monoclonal antibodies to these factors and quantitate their amounts in prostate and prostatic secretions of men with a clinically normal prostate gland and patients with benign prostatic hyperplasia, chronic bacterial prostatitis or prostatic malignancy. We will ascertain whether these prostate growth factors can be linked to toxins such as ricin and whether these PrGF chimeric toxins could be effective in debulking the stromal hyperplasia of BPH. These studies may help elucidate the role of non-steroidal growth factors in the development of BPH as well as other pathological states of the prostate. Further it may lead to a nonsurgical method for treatment of the common male problem of BPH. Presently, surgery is the only effective method of treatment for benign prostatic hyperplasia. However, many men with BPH are elderly and are poor surgical risks. Thus, it would be desirable to have an effective nonsurgical alternative for these individuals.